1. Field of the Invention
The present invention refers to a braking band and to a disc for a ventilated disc brake, particularly, but not exclusively, for applications in the automobile industry.
In particular, the present invention refers to a braking band of the ventilated type suitable for high-performance vehicles.
2. Description of the Related Art
As known, discs of the type specified above consist of two coaxial parts or plates. A first part or plate is suitable for connecting to a support bell that in turn is intended to be connected to a wheel hub of a vehicle. The remaining peripheral part of the disc, which comprises the two plates and is commonly known as braking band, is intended to cooperate with disc brake calipers suitable for exerting a braking action on the vehicle, exerting friction, through pads, on opposite surfaces of the two plates, known as braking surfaces.
It is also known that, during the actuation of the brakes, the friction between the pads of the brake calipers and the braking surfaces of the braking band generates a large amount of heat that needs to be disposed of.
Indeed, the heat generated causes numerous undesired phenomena to occur, like for example the deformation of the braking band, the formation of cracks on the braking surfaces or localised transformations of state of the material constituting the braking band that in turn lead to the deterioration of the braking band itself.
In particular, in applications on high-performance vehicles having high braking efficiency, the energy to be disposed of is very high and the aforementioned need to dispose of the heat generated during braking is even greater.
This need to increase cooling efficiency must however be offset with the further need to keep the bulk of the discs unchanged in order to avoid modifications of the suspension of the vehicle for which they are intended.
These braking bands are present in discs commonly known as ventilated discs. These ventilated discs have undergone a continuous evolution over time, in particular with regard to the number and configuration of the so-called ventilation channels, thus defining the gap that is formed by the two plates axially facing one another. Such ventilation channels are in turn limited on the inside by connection elements that transversally connect the two plates, elements defined as blades or tabs.
For example, from U.S. Pat. No. 5,427,212 tabs are known consisting of curved walls that are repeated with a modular frequency and in which the module itself consists of two tabs one of which is longer than the other.
For example from U.S. Pat. No. 5,526,905 and U.S. Pat. No. 5,526,905 tabs are known consisting of straight walls that are repeated with a modular frequency and in which the module consists of two tabs arranged on two circumferential modules, one inside of the other.
Another example of tabs of this type is known from U.S. Pat. No. 4,712,656.
From U.S. Pat. No. 7,100,748 tabs are known consisting of curved walls that are repeated with a modular frequency in the circumferential direction, in which one of the tabs bends radially coming out from the braking band to form connection elements of the band at the bell of the support disc to the hub of the vehicle.
From WO 2008/136032 tabs are known consisting of curved walls that are repeated with a modular frequency and in which the module consists of two tabs arranged on two circumferential modules, one inside the other.
Finally, from EP 1 352 179 tabs are known consisting of curved walls that are repeated with a modular frequency and in which the module consists of a long tab alongside three short tabs that are radially aligned with one another.
The aforementioned examples of a disc for a disc brake and of braking bands are not able to ensure effective cooling that at the same time ensures that the mass and weight of the disc for a disc brake are kept low.